The present invention claims priority from Japanese Patent Application No. 10-19961 filed Jun. 30, 1998, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates generally to a conference system which utilizes a computer, and more particularly to a method for distributing documents which are used in the conference to each user who participates in the conference.
2. Description of Related Art
In a conference system which utilizes a computer such as a video conferencing system, there are forms in which conference terminals (hereinafter referred to merely as terminals) used by users are directly connected through a circuit and are indirectly connected through a conference control device such as an MCU (multi-point connection device). The conference systems of either form are constituted so that a plurality of users existing in remote places can advance a conference while looking at expressions of the other faces each other and hearing other voices byte distributing real-time data (such as cine image data and voice data which are required for holding a conference in real-time) transmitted from each terminal to other terminals. In addition, such conference systems are constituted so that not only real-time data such as cine images and voices but also information such as documents and still images which are required to advance a conference can be transmitted. The present invention relates particularly to a method for distributing conference records in a conference system of a form in which a plurality of terminals are connected through a conference control device.
As is conventional, in a conference system of the form in which a plurality of terminals are connected through a conference control device, as shown, for example, in Japanese Patent Laid-Open Publication No. Hei 7-322230, documents transmitted from each terminal are made to be distributed to other terminals through the conference control device, and also the conference records are distributed using the same circuit as that used for transmission of real-time data. Similar technique has been disclosed in the columns of Detailed Description of the Invention in Japanese Patent Laid-Open Publications No. Hei 4-167788 and No. Hei 10-51558. In particular, the former publication shows a conception of broadcasting the conference records from the conference control device to a plurality of terminals, and the latter publication discloses an idea in which the conference records have been collected in the conference control device prior to the start of the conference and, each time when a terminal to be participated in the conference is occurred, the conference records are separately distributed from the conference control device to the terminal. However, both publications distribute the conference records using the same circuit as that used to transmit the real-time data.
Incidentally, in the form of a conference system in which a plurality of terminals are directly connected, the conference control device is not included, so that each terminal directly distributes the conference records to other terminals. The literature disclosing such techniques includes Japanese Patent Laid-Open Publications No. Hei 7-321932 and No. Hei 4-167788 (included in the column of Description of the Related Arts). In particular, the former publication discloses an idea such that a particular terminal is made a chairperson terminal which accumulates the conference records from other terminals and then distributes them separately to each terminal, and latter publication shows a conception such that each terminal distributes the conference records to a plurality of terminals by broadcasting. However, both publications distributes the conference records using the same circuit as that used for transmission of the real-time data.
As described above, a conventional conference system distributes the conference records using the same circuit as that used for transmission of the real-time data such as cine image data and voice data. For this reason, there were problems that, when the conference records with large amount of information were distributed, circuit traffic was increased, thereby obstructing transmission of the real-time data such as cine image data and voice data to cause a smooth advance of a conference to be difficult.
Consequently, it is a first object of the present invention to provide a novel method for distributing documents in which the conference records are made to be distributed using a different circuit from transmission of real-time data.
In addition, a conventional conference system of a form in which a plurality of terminals are connected through a conference control device adopts such a configuration that the conference records are always distributed by passing through the conference control device, so that the amount of processing in the conference control device tends to be increased, thereby obstructing transmission of the real-time data to cause a smooth advance of a conference to be difficult.
Thus, it is a second object of the present invention to provide a novel method for distributing documents in which the distribution of the conference records of each terminal is made to be performed without passing through the conference control device.
Further, although there is an idea itself in the prior art in which a broadcast communication is used in distribution of the conference records, an efficient distributing method in a case when a new participant joins during broadcast communication has not been proposed at all.
Accordingly, it is a third object of the present invention to provide an efficient method for distributing documents in which an entire amount of broadcast communication can be reduced as small as possible when a new participant joins during broadcast communication.
A method for distributing documents in the conference system according to the present invention, in the method for distributing documents in the conference system of a form in which conference terminals used by users who participate in a conference and conference control device with a function of distributing real-time data such as cine image data and voices transmitted from the conference terminals to the other conference terminals participating in the conference are connected through first communication lines, is characterized in that broadcasting devices are provided in each of the conference terminals and these broadcasting devices are connected by second communication lines different from the first communication lines, and in that the conference terminals distributing conference records to the other conference terminals distribute the conference records to other destination conference terminals by a broadcast using the broadcasting devices.
In addition, the conference terminal distributing conference records to the other conference terminals is characterized in that, when it receives a notification of a new participant from the conference control device while it is distributing the conference records one by one to the known participants with a broadcast, it continues distribution processing with including the new participant as a destination for subsequent distribution documents, and at the time when it completes the broadcast of the last conference records, it broadcasts the conference records broadcast before the new participant joined to the new participant in turn.